1. Field of the Invention
The present invention, in general, relates to removing specific compounds from gasoline or diesel fuel and, more particularly, to a method for removing sulfur compounds from gasoline or diesel fuel by exposure of the gasoline to a molecularly imprinted polymer.
Sulfur compounds in gasoline, when burned; produce sulfur dioxide which changes the PH of rain toward the acidic, producing acid rain. Numerous well-known environmental impacts are caused by acid rain.
Additionally, sulfur compounds from gasoline that are expelled into the atmosphere contribute to smog and can also cause or aggravate pulmonary irritation. People with asthma, emphysema, and other pulmonary diseases are most deleteriously affected by air born sulfur compound pollutants.
In general, the sulfur compounds in gasoline contribute negatively to the environment and they also cause numerous deleterious health consequences.
The government, accordingly, is in process of regulating sulfur emissions from gasoline and regulations that are intended to lower the level of these emissions into the atmosphere are expected in a few years. In order to decrease sulfur emissions, it is necessary to reduce the sulfur compounds that are present in the gasoline before it is used.
Accordingly, refineries are seeking to find new technologies that can reduce the number and type of sulfur compounds in gasoline prior to use of the gasoline.
However, there are many difficulties that have thus far prevented an effective solution from being found. For example, all current approaches are expensive. The possibility of substantially raising the cost of a gallon of gasoline is not likely to be well-received by the general public.
Furthermore, all current approaches at solving this problem also remove a significant amount of the hydro-carbon content of the fuel, thereby resulting in a lower octane rating and yielding a gasoline that has lower value.
As certain vehicles require a higher octane fuel in order to run properly, the ability of refineries to provide reasonably priced, higher octane rated gasoline with a low sulfur content is, at present, not possible.
The problem is further compounded by the fact that all crude oil is not the same. Gasoline that is produced (i.e., refined) from Saudi Arabia crude oil has a different mix of sulfur compounds that crude oil that is produced from South Africa crude oil, for example.
For a solution to this problem to be especially viable, it must economically remove a variety of sulfur compounds from gasoline without also excessively reducing the hydro-carbon content of the gasoline. In other words, it must be specific as to what compounds are removed from the gasoline, extracting the target sulfur compounds while leaving the other various hydrocarbon compounds that contribute to the energy content of the gasoline.
The need for this technology is becoming increasingly acute. It is expected that upcoming Federal regulations will impose heavy fines on refineries that fail to remove a sufficient quantity of sulfur compounds from the gasoline and possibly diesel fuels that they produce.
Accordingly, a strong financial incentive to solve this problem is motivating the petrochemical industry, yet even so, an effective solution hereto-before has not been possible.
Certain of the more common and deleterious sulfur compounds include thiophene (TP), benzothiophene (BT) and dibenzothiophene (DT). The abbreviations, as shown in parentheses will be used hereinafter.
Accordingly there exists today a need for a method for removing sulfur compounds from gasoline or diesel fuel in ways that help ameliorate the above-mentioned difficulties.
Clearly, such a method would be especially useful and desirable.
2. Description of Prior Art
Processes for removing compounds from non-aqueous solutions are known.
While the structural arrangements of the above described methods, at first appearance, may have similarities with the present invention, they differ in material respects. These differences, which will be described in more detail hereinafter, are essential for the effective use of the invention and which admit of the advantages that are not available with the prior methods.